Alpha Mask

Is the only way that the alpha mask can be modified through the vgMask() API, or does the result of the rendering also modify this buffer.

I’ve played around with the reference implementation, and it looks like that rendering doesn’t change the alpha mask, but I’d like to be sure.

The last paragraph in 7.2 on p.39 has me a bit confused.

Thanks in advance.

Hi Ivo.
The function vgMask is the only way to modify the alpha mask.
As you can see from the specifications, it’s possible to use external VGImage(s) coupled with vgMask function.

Thank you.

Do we always need support alpha mask? From the spec, I think it is an option. But in the vg 1.0 conformance test, it is tested regardless of EGLConfig. What’s your opinon?

The Alpha Mask always needs to be supported.
It’s destination surfaces that contain alpha channels which may or may not be supported based on the EGLConfig().